NEW YORK -- New Orleans Saints players and at least one assistant coach maintained a bounty pool of up to $50,000 the last three seasons to reward game-ending injuries inflicted on opposing players, including Brett Favre and Kurt Warner, the NFL said Friday. "Knockouts" were worth $1,500 and "cart-offs" $1,000, with payments doubled or tripled for the playoffs.

The NFL said the pool amounts reached their height of $50,000 or more in 2009, the year the Saints won the Super Bowl.

The league said between 22 and 27 defensive players were involved in the program and that it was administered by defensive coordinator Gregg Williams, with the knowledge of coach Sean Payton.

The investigation by the league's security department determined that an improper "pay for performance" program included "bounty" payments to players for inflicting injuries on opposing players that would result in them being removed from a game.

In some cases, the amounts pledged were both significant and directed against a specific opposing player, according to the league's investigation. Four former Redskins players, including defensive end Phillip Daniels, told The Washington Post that Williams had a similar system while serving as the Redskins' defensive coordinator.

Matt Bowen, who also played for Williams in Washington, said in a column for The Chicago Tribune on Friday that he didn't regret taking part in the program.

"You do what he (Williams) wants: play tough, push the envelope and carry a swagger that every opponent sees on tape. When you lined up against us, you knew we were coming after you. It was our gig, our plan, our way to motivate, to extra-motivate," Bowen wrote for The Tribune.

"I wanted to be That Guy for him, playing the game with an attitude opposing players absolutely feared," Bowen continued. "If that meant playing through the whistle or going low on a tackle, I did it.

"I don't regret any part of it. I can't. ... Your career exists in a short window, one that starts closing the moment it opens. If making a play to impress a coach or win a game pushes that window up an inch before it slams back down on your fingers, then you do what has to be done."

"There was financial compensation," Wire told the newspaper, which also cited three other anonymous defensive players who confirmed the existence of a bounty program during Williams' time with the Bills.

Wire said he never received a bounty award.

"There were rewards," he said. "There never was a point where cash was handed out in front of the team. But surely, you were going to be rewarded. When somebody made a big hit that hurt an opponent, it was commended and encouraged."

Saints general manager Mickey Loomis failed to stop the bounty program when directed to do so by team owner Tom Benson, while Payton was aware of the allegations but did not pursue them or take steps to stop the "bounty" program, according to the investigation's findings.

"I want to express my sincere regret and apology to the NFL, Mr. Benson, and the New Orleans Saints fans for my participation in the 'pay for performance' program while I was with the Saints," Williams said in a statement. "It was a terrible mistake, and we knew it was wrong while we were doing it. Instead of getting caught up in it, I should have stopped it. I take full responsibility for my role. I am truly sorry. I have learned a hard lesson and I guarantee that I will never participate in or allow this kind of activity to happen again."

The findings, corroborated by multiple independent sources, have been presented to commissioner Roger Goodell, who will determine the appropriate discipline.

"It is our responsibility to protect player safety and the integrity of our game, and this type of conduct will not be tolerated," Goodell said in a statement. "We have made significant progress in changing the culture with respect to player safety and we are not going to relent. We have more work to do and we will do it."

The NFLPA issued a statement Friday, stating it would review the findings.

"Health and safety is a paramount issue to the NFLPA," the statement read. "The NFLPA was informed of this investigation by the NFL earlier today and will review the information contained in the league's report."

Goodell has advised the Saints that he will hold proceedings to determine potential discipline against the team and the individuals involved, and confer with the players' union regarding the appropriate punishment. That discipline could include fines, suspensions and the forfeiture of draft choices.

"I have been made aware of the NFL's findings relative to the 'Bounty Rule' and how it relates to our club. I have offered and the NFL has received our full cooperation in their investigation," Benson said in a statement. "While the findings may be troubling, we look forward to putting this behind us and winning more championships in the future for our fans."

Rita Benson LeBlanc, Tom Benson's granddaughter and team co-owner/executive vice president, twice declined to comment on the situation when asked by ESPN.com on Saturday at the MIT Sloan Sports Analytics Conference in Boston. Benson LeBlanc was not asked about the bounty system during her panel discussion at the conference.

According to the investigation, the players regularly contributed cash into a pool and received improper cash payments of two kinds from the pool, based on their play in the previous week's game.

Williams administered the program with the knowledge of other defensive coaches and occasionally contributed funds, according to the league investigation.

Payments were made for plays such as interceptions and fumble recoveries. But the program also included "bounty" payments for "cart-offs," meaning that the opposing player was carried off the field, and "knockouts," meaning that the opposing player was not able to return.

"The payments here are particularly troubling because they involved not just payments for 'performance,' but also for injuring opposing players," Goodell said in a statement. "The bounty rule promotes two key elements of NFL football: player safety and competitive integrity."

A team source familiar with the investigation told SI.com that Saints linebacker Jonathan Vilma offered $10,000 to any defensive player that knocked Favre out of the 2009 NFC Championship Game.

Favre, who absorbed multiple hard hits in the game, told SI.com: "I'm not pissed. It's football. I don't think anything less of those guys."

Favre's agent, Bus Cook, said he was unaware of the investigation until Friday. He said the Saints should have been penalized for several hard, late hits during the 2009 NFC Championship Game and that he believed the contact was not coincidental.

"It was pretty obvious that the intent was to take Brett out of the game, and it happened the week before with Kurt Warner, too," Cook said. "I don't know anything about whether it was by design or whatever, but I think a lot of people shared that same viewpoint that there were some hits that didn't get called."

Cook, however, said Favre never suggested to him he was maliciously targeted.

"That's part of football, getting hit," Cook said. "Brett never complained to me one way or another."

The NFL has a longstanding rule prohibiting "non-contract bonuses," and they violate both the league constitution and bylaws and the collective bargaining agreement with the players' union. Clubs are advised every year of this rule in a memo from the commissioner.

"Our investigation began in early 2010 when allegations were first made that Saints players had targeted opposing
players, including Kurt Warner of the Cardinals and Brett Favre of the Vikings," Goodell said in a statement. "Our security department interviewed numerous players and other individuals.

"At the time, those interviewed denied that any such program existed and the player that made the allegation retracted his earlier assertions. As a result, the allegations could not be proven," Goodell said.

"We recently received significant and credible new information and the investigation was re-opened during the latter part of the 2011 season."

Warner, who retired after the 2009 season, responded to a fan's comment on Twitter that even if the Saints had a bounty program a playoff hit on Warner was clean. Warner tweeted, "I would have to agree with you!!!"

"I don't want to say that there was an attempt to injure, but I definitely think there were games where I could tell you that it seemed that they went beyond what was normal in regard to when they were going to hit me or how they were going to hit me," Warner said on the NFL Network. "Again, not with the intention necessarily of hurting me, but knocking me out of my game to get me to think about things differently. If by chance they hit me and knocked me out of the game, maybe that's a benefit for them."

Chicago Bears wide receiver Earl Bennett was injured by a hit from Roman Harper, who was not flagged or fined, in a Week 2 loss to the Saints. Bennett missed five weeks with a chest injury.

"All I have to say is I hope we play them again," Bennett told ESPNChicago.com Friday. "The game of football is a contact sport, so if they're gunning for me, I'm going to be gunning for them."

Williams employed a similar system while with the Redskins from 2004-07, according to a report Friday in The Washington Post.

Three former players said Williams handed out thousands of dollars in accordance with a specific scoring system, including "kill shots" that resulted in opposing teams' top players being knocked out of the game.

Daniels, however, went on the record in the Post report and defended Williams.

"I think it is wrong the way they're trying to paint (Williams)," Daniels told the Post. "He never told us to go out there and break a guy's neck or break a guy's leg. It was all in the context of a good, hard football."

Daniels told the Post it was his understanding that Williams started the "bounty" program with money collected from fines for players being late for practices and meetings.

"Rather than pocket that money or whatever, he would re-distribute it to players who had good games or good practices," Daniels told the Post.

Daniels told the Post the most money he ever received was $1,500 for a four-sack game against the Cowboys in 2005.

According to the NFL investigation of the Saints, Benson was not initially aware of the bounty program and directed Loomis to make sure it was discontinued immediately. The evidence showed Loomis did not do so, investigators found.

"Similarly, when the initial allegations were discussed with Mr. Loomis in 2010, he denied any knowledge of a bounty program and pledged that he would ensure that no such program was in place. There is no evidence that Mr. Loomis took any effective action to stop these practices," according to the league's findings.

Payton "was not a direct participant in the funding or administration of the program," according to the investigation.

However, Payton "was aware of the allegations, did not make any detailed inquiry or otherwise seek to learn the facts, and failed to stop the bounty program. He never instructed his assistant coaches or players that a bounty program was improper and could not continue," the investigation found.

The investigation included the review of approximately 18,000 documents totaling more than 50,000 pages, interviews of
a wide range of individuals and the use of outside forensic experts to verify the authenticity of key documents.

A memo sent by the NFL to all 32 teams detailing the investigation was obtained by CBS Sports, which reported that Michael Ornstein, a former marketing agent with close ties to Payton and former Saint Reggie Bush, contributed to the bounty fund.

Ornstein, who served time in prison for fraud, pledged $10,000 to the quarterback bounty in 2009, and contributed money at least twice in 2011, according to CBS Sports.

According to CBS Sports, the memo also details an email sent from Ornstein to Payton, which outlined the bounty system.

The NFL's most infamous bounty case occurred in 1989 when Eagles coach Buddy Ryan was accused of putting a bounty on Cowboys players.

On Thanksgiving Day, Cowboys coach Jimmy Johnson accused Ryan of putting a bounty on Dallas quarterback Troy Aikman and placekicker Luis Zendejas before a 27-0 Philadelphia victory. Ryan and his players denied the charges and NFL commissioner Paul Tagliabue found no evidence of wrongdoing.

Information from ESPN NFL Insider Adam Schefter, ESPNChicago.com and The Associated Press was used in this report.